The invention relates to drains for building floors, basements, exterior paved areas, and the like. The invention provides floor drain assemblies and check valves providing improved drainage performance and minimized backflow, particularly where drainage is an irregular occurrence.
U-shaped or xe2x80x9cgooseneckxe2x80x9d traps have long been used in the plumbing industry to prevent backflow of harmful or annoying sewer or pipe gasses into buildings while permitting drainage of unwanted water from floors and other horizontal surfaces. Such traps operate by leaving a small quantity of fluid within the lower portion of a U-shaped trap section to act as a gas barrier. In many applications, however, particularly where access is difficult or where drainage is infrequent, it is disadvantageous to use such drains. Fluid may evaporate from the trap, permitting free flow of obnoxious gases through the drain; insects may breed in the fluid, or in some instances the fluids may harden so as to actually block or restrict flow through the drain. Such conventional drains are also relatively difficult and expensive to install. In addition to floor drain applications, these problems are also common to other areas of fluid control, wherever fluid drainage is an occasional problem.
One solution to these problems has been the use of trap primers, which operate to ensure that a minimum level of fluid is left in the drain to act as a trap for gasses, which accumulate within drains. Trap primers are usually difficult and expensive to install, and require maintenance and constant monitoring to ensure their functionality.
Outside the floor drain environment, the use of check valves has been suggested. As demonstrated herein, check valves can be efficient both in facilitating draining operations and in trapping drain-pipe gasses and preventing backflow. Heretofore, however, no one has suggested placing simple and efficient check valves in floor drains, either alone or in combination or in series with other types of valves.
The invention provides improved floor drains of unprecedented simplicity and reliability. In one aspect, the invention provides a check valve for a floor drain, the check valve being adapted for disposition within a floor drain or a drain basin and comprising a stop adapted for sealing engagement of a drain sealing surface located proximate an inlet to said floor drain, and further comprising means adapted to urge the stop into sealing engagement with the drain sealing surface. The means for urging the stop into sealing engagement with the drain sealing surface is adapted to permit disengagement of the stop from the sealing surface as a fluid such as water enters said drain, so as to permit drainage of the fluid through the drain is permitted, while urging the stop back into contact with the sealing surface so that backflow of gasses from within said drain is prevented after the fluid has drained. Improved drain and valve assemblies provide redundant gas-trap and backflow prevention protection through the simple, economical, and efficient application of check valves. Redundant layers of check valves are installed in series to permit one-direction fluid flow and vacuum relief in drains.
In one aspect, the invention provides a drain assembly for use in the drainage of drain surfaces such as building and basement floors, exterior paved areas, swimming pools, and the like. The most common application of this aspect of the invention is in the drainage of water from flooded areas, with the water flowing downward under the influence of gravity or some other driving force. Most often, this means that the fluid drains substantially vertically under gravitational influence. An assembly according to this aspect of the invention comprises a drain basin having an inlet and an outlet, with the outlet being adapted for the attachment of a drain conduit, and at least one check valve disposed within the drain basin. In an alternative embodiment, at least two check valves can be placed in series to form a set, preferably in a substantially vertical orientation, so that a chamber is formed between the valves. Two or more sets can be used in parallel, or in series if desired, or some combination thereof. The check valves are adapted, generally by a combination of their substantially vertical series orientation and by the use of valves having suitable design opening or actuating pressures, to permit drainage of fluids through the drain inlet without substantial restriction, and to prevent backflow of gasses from the drain conduit through the chamber to the inlet. Preferably, valves are selected with opening and/or actuating pressures suitable for allowing gasses, for example air, to flow through the drain inlet and the chamber to relieve any vacuum formed within the drain conduit. The check valves are supported in a removable framework or other structure so that the valves may be removed from the drain for cleaning, repair, replacement, or other maintenance.
In another aspect, the invention provides a valve assembly for use with drains for draining drain surfaces. A valve assembly according to this aspect of the invention comprises a preferably removable support structure adapted for disposition, preferably by insertion, within a drain basin installed in a floor or other drain surface. The support structure is adapted to support either a single check valve, or a plurality of check valves so as to form at least one chamber between serial individual valves or sets of valves, and to permit drainage through the drain in the manner described herein.
Check valves used with the invention are of various types. For many applications, and in particular where the drain is intended to facilitate drainage of water from floors and the like, flapper valves having flexible diaphragms adapted to engage a circumferential seat, and optionally comprising backing plates to support the diaphragm, and spring-loaded or spring-biased valves, are preferred. The selection of suitable check valves for any given drainage application will not trouble the designer of ordinary skill in the pertinent art.
Other preferred embodiments of this check valve aspect of the invention comprise stops incorporating xe2x80x9cflapperxe2x80x9d diaphragms made of elastic material, such as natural or synthetic rubbers, or other polymers. The diaphragm in such embodiments has sufficient flexibility to flex under pressure or other action of liquid entering the drain in order to allow the liquid to drain, and to return to a substantially unflexed condition in which sealing engagement of the drain sealing surface by the diaphragm is restored following drainage of said liquid. In such embodiments, as may be seen, the elasticity of the diaphragm acts as the means for urging the diaphragm into sealing contact with the drain sealing surface. A particular advantage of such embodiments of the invention is that the elastic diaphragm may be relatively easily, through well known liquid static and dynamic principles, and through well known principles of structural mechanics, be adapted to flex under the action of a preselected head pressure when liquid is present within the drain. That is, the geometry, and therefore the stiffness, of a diaphragm made of any given elastic material may be selected to ensure that the valve will open when a desired amount of water is present in the drain. As will be readily understood by those of ordinary skill in the art, once the suggestion has been made, this purpose may be accomplished either by selecting an appropriate uniform thickness for the diaphragm or by tailoring the thickness to provide a non-uniform thickness having any of a wide variety of desired flexure or bending characteristics. Another way of controlling flexure in the diaphragm, as will be well understood by those of ordinary skill in the art, is to provide the elastic diaphragm with a back plate which serves to stiffen or otherwise support at least a portion of the diaphragm. In such cases portions of the diaphragm supported by the back plate will have a generally increased stiffness, as compared to non-backed portions of the diaphragm.
In other preferred embodiments of the invention the check valve is spring-biased, such that the means for urging the stop into contact with the drain sealing surfaces comprises a spring. As will be readily apparent to those having ordinary skill in the art, in such embodiments it is a relatively straightforward matter, once the idea has been suggested, to select or adapt a spring having an appropriate thickness for permitting disengagement of the stop from the sealing surface when a selected head pressure had been reached inside the drain.
Yet another embodiment of a drain assembly according to the invention comprises a collapsible, flexible, one-way valve, referred to herein as a sheath valve. The sheath valve can be disposed within the interior of the existing drain conduit or a drain basin adapted for attachment to the existing drain conduit. The drain basin comprises an inlet portion, which is preferably bowl-shaped, and which is adapted to receive fluid entering the basin. The sheath valve also comprises an outlet portion having at least one substantially rigid, generally axially oriented longitudinal member, which may be co-molded or otherwise integrally formed, or may be assembled of separate and distinct parts, and a generally axially oriented flexible portion adapted to collapse against the rigid peripheral portion. The substantially rigid and flexible portions form a conduit adapted to transfer fluid from the drain to the drain conduit, via the inlet portion. By collapsing against the rigid portion, as it is biased to do, the flexible portion acts to prevent entry of gasses to the outlet portion of the valve when a pressure within the inlet portion is less than or equal to (that is, not greater than) the pressure outside the outlet portion. When fluid is introduced to the inlet of the sheath valve, the rigid and flexible portions separate under pressure from the fluid, opening the valve so as to allow drainage of the fluid through the valve.
In another variation drain assemblies according to the invention sheath valves are formed from a flexible elastomeric material such that the sheath valve is entirely collapsible. The sheath valve comprises an inlet portion adapted to receive a fluid, and an outlet portion. In this variation the outlet portion comprises no rigid walls, because the elastomeric material has memory properties that allow the sheath valve to open when fluid is passing through the valve and then return to its initial shape when fluid is no longer flowing through the valve. The flexible walls of the outlet portion are biased toward a collapsed position and the valve is opened under pressure from a draining fluid, but entry of gasses to the outlet portion (when a pressure within the inlet portion is not greater than a pressure outside the outlet portion) is prevented. Additionally, a plate may be provided beneath the inlet portion of the valve, the plate being configured so as to deflect the outlet portion of the sheath, and thereby to assist biasing of the sheath walls toward the closed position.
Yet another embodiment of the drain assembly according to the invention comprises a drain basin, a plurality (preferably 3 or more) of substantially vertically arranged support slides, and a valve provided with a plurality (preferably 3 or more; generally in the same number as the support slides) of dependent struts. The drain basin has an interior and is adapted for the attachment thereto of a drain conduit. The substantially vertical support slides are disposed within the interior of the basin and have upper and lower ends, the upper ends being more closely spaced from each other than the lower ends. The valve comprises a plurality of depending struts, the struts being flexible and including distal ends adapted to engage the support slides. The struts are biased, by molding during forming or otherwise, toward positions which are radially extended to an extent to which they provide positive contact in the support slides, so that engagement of the support slides by the struts biases the valve into the closed position, in which the valve seals the drain conduit, but not with so great a force that the introduction of a fluid within the basin will be prevented from causing the valve to move downward, with the struts sliding along the support slides, the valve providing increasing resistance as it is pushed further down, flexing as progressively further as the valve moves downward, breaching the seal between the valve and the drain conduit and allowing drainage of the fluid from the basin. Thus greater pressures of water acting against the valve cause the valve to open more fully, thus increasing drainage flow, but when pressure in the drain basin is reduced, the valve closes.
Yet another embodiment of the drain assembly according to the invention comprises a drain basin attached to a drain conduit and a valve having a plurality of flexible tabs disposed proximate to the drain conduit, the tabs being so sized and shaped as to fit together in a closed configuration in which escape of gas from the drain conduit is prevented when no fluid is present in the basin. The tabs are adapted to deflect under pressure of a fluid draining from said basin, so as to allow drainage, and are biased toward the closed configuration. An optional addition to drain assemblies of this type is a funneling or channeling means adapted to channel fluid entering the basin onto the tabs so as to increase the efficiency of drainage from the basin by increasing the force applied by the draining fluid on the tabs.
An important advantage offered by drain valves according to the invention is that they may be provided either as integral parts of new drain assemblies or with separate housings to that they may be inserted in existing drain structures as retrofits. Thus new drains omitting P- or U-traps may be built, or existing drains having such traps may be provided with the advantages described herein. Likewise, stuck or damaged valves may be easily replaced. In preferred embodiments, the advantage of interchangeability or removability is easily provided by providing the check valve and the biasing means with a housing. Such a housing may be used with or without separate gaskets, etc., for sealing the drain, and may easily be adapted such that the housing itself provides the sealing surface engaged by the stop for sealing of the drain.
Another advantage offered by drain valves according to the invention is that they are readily adapted to a wide variety of drains. For example, they are easily provided in substantially circular section, for use in a standard circular or cylindrical drain pipe or as easily provided with a rectangular or other non-standard section.
Yet another distinct advantage offered by check valves according to the invention is that they are easily installed or used in conjunction with other valves or with existing traps, so as to provide redundant valve structure and the advantages associated therewith. For example, two or more check valves according to the invention may be used together, so that if one becomes jammed or otherwise dysfunctional the other may continue to serve satisfactorily. Likewise, all of the other advantages and improvements described herein, such as the provision of the valve assembly with a housing to permit the valves to be retrofitted or removed for maintenance or replacement, are enjoyed by those embodiments incorporating additional valves.
In addition to the check valves and drain assemblies described herein, as such, it is to be understood that all new and useful devices or components described herein are considered to constitute a part of the invention, claimable in their own right, whether such is stated with particularity herein or not.